The proposed research is to evaluate the process of habituation and the brain mechanisms involved in habituation. Habituation will be studied within the response systems of lick suppression, startle response, EEG arouael, and locomotor exploration. Differences in the central control of these various response measures will be studied. The particular emphasis throughout the research will be on the long-term effects of habituation and possible distinctions between short-term and long-term habituation both in terms of behavioral variables and neural control. Bibliographic references: Leaton, R. N. Long-term retention of the habituation of lick suppression in rats. Journal of Comparative and Physiological Psychology, 1974, 87, 1157-1164.